An Observational Study of Errors Related to the Preparation
and Administration of Medications Given by Infusion Devices
in a Teaching Hospital

Since there is no detailed hospital based incident reporting system, this study was designed to evaluate the medication errors associated with infusion pumps in intensive care unit (ICU). The investigation was conducted in a Teaching hospital in the form of a prospective, observational study. A sample size of 43 doses administered to ICU patients was chosen to enable reliable estimate of error rates. Any deviation in the IV pumps implication from the guidelines and/or doctor’s order in the charts was measured as the main outcome. Forty three doses with 258 opportunities for error were observed. Twenty (7.8%) errors were detected, of which 14 (20%) were incorrect dose, 4 (20%) labeling error, 2 (10%) unauthorized medication. From incorrect doses, 8 (57%) resulted in overdose. Benzodiazepines were the most common class of drug involved. We concluded that regarding the infusion pump usage for drug delivery, a large number of errors exist.

Since there is no detailed hospital based incident reporting system, this study
was designed to evaluate the medication errors associated with infusion pumps in
intensive care unit (ICU). The investigation was conducted in a Teaching
hospital in the form of a prospective, observational study. A sample size of 43
doses administered to ICU patients was chosen to enable reliable estimate of
error rates. Any deviation in the IV pumps implication from the guidelines
and/or doctor?s order in the charts was measured as the main outcome.

Forty three doses with 258 opportunities for error were observed. Twenty (7.8%)
errors were detected, of which 14 (20%) were incorrect dose, 4 (20%) labeling
error, 2 (10%) unauthorized medication. From incorrect doses, 8 (57%) resulted
in overdose. Benzodiazepines were the most common class of drug involved. We
concluded that regarding the infusion pump usage for drug delivery, a large
number of errors exist.

Medication errors are defined as any preventable event that may cause or lead to
an inappropriate medication use or patient harm while in the control of the
health care professional, patient or consumer (1). Approximately 1-2% of
patients admitted to the United States hospitals are harmed as a result of
medication errors (2). Several medication adverse events which led to deaths
have been reported with infusion pumps (3). Administration by continuous
infusion, potentially, has a higher risk for medication errors. If calculations
are required for drug administration, this added step in the use process can
contribute to increased rates of errors (4).

Also, calculations for continuous infusion are more complex and can be more
error prone than that of intermittent administration. Continuous Intravenous
infusions are usually administered by infusion pumps. The scope of this problem
is complicated, since infusion pumps are mostly being used for specific drugs
e.g. high-alert medications (5) and ICU patients. Currently, no ICU floor-based
pharmacist is available in the ICU of our hospital to get involved in IV
admixture and/or administration.

Errors are more common in intensive care units probably because of
poly-pharmacy, a more stressful environment and unconsciousness of the patients
who may not be able to verbalize symptoms. Medication adverse events involving
critically ill patients can be potentially life-threatening (6, 7).
Failure to accomplish what was ordered and planned is a type of error that has
been less identified and discussed compared to other types of medication errors.
The topic is of high priority for clinicians. There is value to better
understanding the issues surrounding intravenous infusion. Thus, the present
study was performed to evaluate types, frequency, and severity of medication
errors associated with infusion pumps in our ICU.

Experimental

This investigation was conducted in the National Research Institute of
Tuberculosis and Lung Disease between May to June 2006. The hospital is one of
the largest teaching hospitals in Tehran with 446 inpatient beds. Only ICU was
included in the study because of low infusion pump usage in the other wards. It
is a multidisciplinary 12 bed ICU with a nurse:patient ratio of 1:2. There is no
floor-based pharmacist currently available in ICU.

The study was approved by the ethical committee of the hospital. All IV
medications were prepared and administered on the wards by nursing staff. We did
not need informed consent from nursing personnel to perform this type of study.
To decrease observer induced bias, the nursing staff were not aware of the
purpose of this study. They were told that this is part of a clinical pharmacy
training program, if they asked the observer about what he/she was recording.

A cross-sectional, prospective approach was used to identify any error related
to medication administration via infusion pumps that could be assessed during
the observation period. The process was verified by a clinical pharmacy
resident. The observer intervened for errors likely to cause imminent harm,
during the observation process.

A sample size of 43 doses was chosen. The pumps which employed for medication
delivery were ?Atom syringe 1235N (made in Japan) for adult and neonates?.
Manual of the infusion pump, package insert of the medications, and nursing
hospital guidelines for preparation were reviewed. A check list of potential
errors was created for the observer to record details of each IV drug
preparation and administration via infusion pump. The potential errors were
listed as documentation of the order rate, patient identification, date, and
time that the infusion was started or changed on the label of the infusing
medication, unauthorized medication or change of order which was not found in
the charts, the non-consistency of the concentration and rate with physician?s
order, the compatibility of the concomitant drugs, observation of any leakage
from any part of infusion set, and detachment of patient from the pump.

Error was defined as any deviation in implication of the IV pump from the manual
instructions and/or doctor?s order in the charts.

NCC MERP Index for categorizing medication errors was used to determine the
severity of errors (8). In categories B to D error but no harm occurred, and in
categories E to H harm has been caused.

A new calculation for pump was made whenever the order changed. The accuracy of
physician?s order was not evaluated in this investigation.

Results

We observed forty three doses which were administered via infusion pumps, with
258 opportunities for error (43 multiplied by 6 potential errors, which is
mentioned below). Twenty (7.8%) errors were detected, including14 (70%)
incorrect dose, 4 (20%) labeling error, and 2 (10%) unauthorized medication. All
the patients were attached to the pumps at the time of observation. Also, no
leakage from infusion set monitoring was detected. We could not find any
incompatibility in the solution (Table 1).

From incorrect doses, 8 (57%) could result in overdose if not corrected by the
observer. Midazolam, which is a benzodiazepine, was the most common drug
involved in the likely overdose (38%). This was prevented from reaching the
patient, due to intervention the observer?s.

The result of this study shows that since medication errors with infusion pumps
seem to occur mostly because of a lack of knowledge or precision in preparation
and administration procedures, they could be easily corrected by educating the
nursing staff.

Detachment of patient from pump was selected as a potential error, based on a
previous experience in other wards where patients were mobile enough to detach
themselves from the pumps. This was not seen during the observation period, due
to the selected setting (ICU) of this study.

We found a number of error prone drugs, including those which are less routine
such as sufentanil and those which are prepared for emergency reasons such as
dopamine. Midazolam was the most frequent drug associated with errors, probably
due to more frequent use of this drug. Calabrese et al observed the most
frequent medication administration error in an adult ICU with vasoactive
substances (9). Labeling error was seen in 20% of errors, despite the fact that
all the diluents used were chosen correctly according to the hospital
guidelines. Incorrect labeling and wrong diluents were reported to be up to 99%
and 49%, respectively, of the doses administered in German hospitals (9).

Seventy percent of the errors were due to incorrect dose. Pre-calculated drug
concentration charts, according to different routine rates, are useful tools and
could be applied in wards like ICUs where nurses are overloaded with several
problems and in wards that there are not enough trained pharmacists to calculate
and mix the IV preparation with the appropriate solutions. Palm and pocket PC
software and computer-based database driven calculator (10) are now available to
provide a spreadsheet with suitable rate, for dose calculations, in order to
avoid errors. It has been shown that defining and classifying medical errors
could help the reporting system of an institution to guarantee patient safety
(11). Hence, we described different categorization in an effort to find better
perception of the errors caused.

Since our health system is devoid of a well organized reporting system, errors
are not detected and consequently not prevented. Le Grognec and the colleagues
have discussed similar issues in their system (12).

It was also shown that the most common reported reason for errors are
performance deficit, which could be overcome by education (13). Performance
level failures have been demonstrated as slips and lapses rather than knowledge-
associated mistakes (14).Individual flaws were addressed as the main flaws in
the medication delivery systems (15). Contributing factors to errors are lack of
concentration, and distractions (nurses are vulnerable to several interruptions
which may affect working focus). The goal of monitoring was to provide
guidelines for nurses to decrease ICU medication errors regarding infusion pump
drug deliveries. Protocols are more helpful for newly graduated nurses to
promote their patient care services (16). This may contribute to a decreased
prolongation of patient?s stay, cost, resource consumption, adverse drug
reaction, overdose, subtherapeutic dose, as well as an increased patient safety
and efficiency of health care services in our ICU.

Alternative dosage calculation techniques should be applied to reduce the risk
of errors (17). Improved training of nurses in calculating dosage is necessary
to avoid risk associated with drug preparations.

In conclusion, medication errors have recently drawn significant attention,
since they could cause considerable morbidity, mortality and unnecessary costs.
The concept that clinical pharmacists can have a positive impact on patients?
pharmaceutical care is becoming widely accepted (18).
Although no significant clinical outcomes have been encountered in the present
investigation, possibly because the observer has intervened where needed,
re-engineering of this high risk activity is suggested. Implementing a system
with more active involvement of hospital pharmacists and/or clinical pharmacists
in such activities can lessen the medication error related problems and thus
enhance patient safety to a substantial degree. Data on frequency and type of
medication errors is one of the several measures of patient safety which should
be further completed with data on outcome measures.

The major limitation of this study was the small sample size. Although we
claimed that nurses were unaware of this study?s purpose, they might have
guessed and, this could influence the rate of error if we had extended the
study. Of course, our findings should further be verified by larger sample size
and inclusion of wards with less pressured environment.

Acknowledgment

We would like to thank the ICU staff for their assistance during data
collection.